The present invention relates to a transmission line resonator, and more specifically, to a speed of light referenced frequency oscillator.
The generation of signals having frequencies with wavelengths on the order of millimeters (mm-waves) is challenged by the lack of low phase-noise oscillators that work at the carrier frequency and have a large tuning range. On-chip complementary metal-oxide-semiconductor (CMOS) variable capacitances (varactors) have low quality factors (Qs) (e.g., less than 10). As a result, a voltage-controlled oscillator (VCO) based on integrated varactors may have a high phase noise and a limited tuning range. Currently available high-Q on-chip resonators are not only bulky but also have no means to tune their frequency characteristics. Alternative devices use a phase-locked loop (PLL) working at lower frequencies and frequency multipliers (e.g., doublers, triplers) to generate a mm-wave carrier. These multiplying devices need active devices and passive devices such as inductor and capacitors. Moreover, these multipliers have poor efficiency. As a result, there is a power penalty and area penalty to generate the higher frequencies. In addition, the generated signals at mm-waves need amplifiers and buffers to drive the up/down conversion mixers.